You are learning Serbian for a while and you feel confident when it is about grammar rules, writing or understanding. But when you need to communicate in a real life, you are experiencing some difficulties and you are a little bit discouraged by that.
If that is the case, the solution is - talking and only talking. Practice communication and use your Serbian on daily basis as much as possible.
For these exercises, you will need to have a language partner - Serbian speaker. Ask somebody to help you, most of the people will gladly accept. Doesn't matter if they are native or non native Serbian speakers or if the conversation goes alive or online. Pick your role, and - start practicing your Serbian!